How severe is CVE-2026-42449?

CVE-2026-42449 has a CVSS score of 8.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2026-42449?

CVE-2026-42449 affects the following packages: n8n-mcp (npm). Ecosystems affected: npm.

How do I fix CVE-2026-42449?

Update n8n-mcp to 2.47.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-42449 is resolved across your whole dependency graph.

How do I detect CVE-2026-42449 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for n8n-mcp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-42449 if there is no patch (or I can't update yet)?

Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Is CVE-2026-42449 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-42449 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-42449?

CVE-2026-42449 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 11th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-42449?

CVE-2026-42449 is classified as Server-Side Request Forgery (SSRF) (CWE-918). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-42449 published, and has it been updated?

CVE-2026-42449 was published on May 7, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

HIGH severity

CVE-2026-42449 — n8n-mcp

HIGHFix: czlonkowski/n8n-mcp@9639f75

CVE-2026-42449 is a high-severity (CVSS 8.5) Server-Side Request Forgery (SSRF) vulnerability in n8n-mcp. A fix is available for n8n-mcp — see the affected versions and patch details below.

n8n-MCP: IPv4-mapped IPv6 addresses bypass SSRF protection in validateUrlSync(), enabling full SSRF for SDK embedders

Also known asGHSA-56c3-vfp2-5qqj

Published

May 7, 2026

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Nov 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-42449.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs11th percentile — riskier than 11% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

0other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

n8n-mcpnpm

50Kdownloads / week

Description

Impact

In the SDK embedder path (N8NDocumentationMCPServer constructor, getN8nApiClient(), and validateInstanceContext()), the synchronous URL validator in SSRFProtection.validateUrlSync() had no IPv6 checks. IPv4-mapped IPv6 addresses such as http://[::ffff:169.254.169.254] bypassed the cloud-metadata, localhost, and private-IP range checks. An attacker able to supply an n8nApiUrl value could cause the server to issue HTTP requests to cloud metadata endpoints (AWS IMDS, GCP, Azure, Alibaba, Oracle), RFC1918 private networks, or localhost services. Response bodies are returned to the caller (non-blind SSRF), and the n8nApiKey is forwarded in the x-n8n-api-key header to the attacker-controlled target.

The first-party HTTP server deployment was not primarily affected — it has a second async validator (validateWebhookUrl) that catches IPv6 addresses.

Impact category: CWE-918 (Server-Side Request Forgery).

Affected

Deployments embedding n8n-mcp as an SDK using N8NDocumentationMCPServer or N8NMCPEngine with user-supplied InstanceContext on versions v2.47.4 through v2.47.13.

Patched

v2.47.14 and later.

npm: npx n8n-mcp@latest (or pin to >= 2.47.14)
Docker: docker pull ghcr.io/czlonkowski/n8n-mcp:latest

Workarounds

If developers cannot upgrade immediately:

Validate URLs before passing to the SDK — reject any n8nApiUrl whose hostname is an IP literal (bracketed IPv6 or dotted IPv4) before calling N8NDocumentationMCPServer / getN8nApiClient(). Accept only URLs with DNS-resolvable hostnames.
Restrict egress at the network layer — block outbound traffic from the n8n-mcp process to RFC1918 ranges (10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16), link-local 169.254.0.0/16, and cloud metadata endpoints. Defense-in-depth against this class of issue and recommended even after upgrading.
Do not accept user-controlled n8nApiUrl values — if the project's integration derives the URL from internal configuration only, this vulnerability is not reachable.

Upgrading to v2.47.14 is still strongly recommended.

Credit

Reported by @manthanghasadiya.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`n8n-mcp`	≥ 2.47.4&&< 2.47.14	2.47.14`npm install n8n-mcp@2.47.14`

Affected Products

1 product · 1 configurations

Application

n8n-mcpn8n-mcp

≥ 2.47.4 && < 2.47.14

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for n8n-mcp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update n8n-mcp to 2.47.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-42449 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.

Frequently Asked Questions

### Impact In the SDK embedder path (`N8NDocumentationMCPServer` constructor, `getN8nApiClient()`, and `validateInstanceContext()`), the synchronous URL validator in `SSRFProtection.validateUrlSync()` had no IPv6 checks. IPv4-mapped IPv6 addresses such as `http://[::ffff:169.254.169.254]` bypassed the cloud-metadata, localhost, and private-IP range checks. An attacker able to supply an `n8nApiUrl` value could cause the server to issue HTTP requests to cloud metadata endpoints (AWS IMDS, GCP, Azure, Alibaba, Oracle), RFC1918 private networks, or localhost services. Response bodies are returned